Solenoid construction



SOLENOID CONSTRUCTION Filed Jan. 10. 1955 United States Patent Ofiice 2,889,497 Patented June 2, 1959 SOLENOID CONSTRUCTION Forrest R. Wolf, Arlington Heights, and Frank E. Cerveny, Berwyn, 111., assignors to The Dole Valve Company, Chicago, 11].

Application January 10, 1955, Serial No. 480,714

6 Claims. (Cl. 317-158) The present invention relates to a solenoid construction, and more particularly to a new and improved solenoid which, by virtue of the construction features of the present invention, has a considerably reduced tendency for arcing between the solenoid coil leads and/or the solenoid coil windings.

Although solenoid constructions embodying the principles of the present invention have general utility, they enjoy particularly advantageous use in such installations where it is advantageous to have a plug-in type solenoid. One such installation would be in solenoid operated valve structures wherein it is often preferred to have a plug and socket electrical connection from the source of energy to the solenoid actuated valve or from the valve control system to the solenoid actuated valve.

In such plug-in type solenoid constructions heretofore known, the construction technique has frequently been such that the leads from the coil which is wound on the spool have either been so close to each other or to the winding convolutions of the coil, which are at a very different potential from one or the other of the leads, that there has been a strong tendency for arcing between these several parts, with a resulting breakdown of the coil and a requirement for replacing the same in order to put the mechanism operated thereby in an operative condition.

More particularly, one of the techniques of solenoid winding construction has been to bring both of the lead wires out from a single end of the coil, with the result that when the lead wires are secured to terminals, the lead wire from the inner windings of the coil passes close to the outer windings of the coil which are of substantial and maximum opposing voltage from the inner lead wire. This maximum voltage strain between the inner lead wire and the outer coil windings frequently resulted in a breakdown of the insulation and arcing between these parts so that the coil was shorted out or burned and was no longer capable of properly functioning. To obviate this difiiculty, means such as an insulating washer has been provided to insulate the lead wires from the coil wind ings. This effort to obviate the stated difiiculty was not too successful, however, since the arcing continued to occur between the outer windings and the inner lead wire, the arcing occurring over the peripheral edge of the washer.

It is, therefore, an important object and feature of the present invention to provide a solenoid construction in which the hereinabove described tendency for arcing between the leads and the solenoid windings and between the leads and a metal arcing will be reduced and the arcing is substantially prevented. This important feature of the present invention has been provided by the inclusion of insulating means in the solenoid construction which overlies the peripheral edge of the split insulating washer which separates the coil windings from the leads. This insulating member overlying the peripheral edge of the washer may be formed as a skirt on an insulating pants and disk member which also insulates the inner end portions of the terminal lugs on one of the flanges of the solenoid spool.

It is, therefore, another important feature of the present invention to provide a new and improved disk and pants insulator member with a skirt to overlie the end flange of the solenoid spool and further to overlie the insulating washer which separates the coil leads from the coil windings.

Still another object and important feature of the present invention is to provide a new and improved solenoid construction wherein the spool has terminal lugs afiixed to one of the end flanges thereof, and a disk and pants insulating member is retained thereon with a skirt on the insulating member overlying on and of the solenoid coil.

Still other objects, features and advantages of the present invention will become readily apparent to those skilled in the art and to others from the following detailed description of the present invention and an embodiment thereof, from the claims, and from the accompanying drawings, in which each and every detail shown is fully and completely disclosed as a part of this specification, in which like reference numerals refer to like parts, and in which:

Figure 1 is an elevational view of a complete solenoid construction embodying the principles of the present in vention;

Figure 2 is a fragmental sectional view of the terminal end portion of the solenoid construction of Figure 1 and is viewed as taken substantially along the line II-II of Figure 1;

Figure 3 is a fragmental sectional view which is similar to Figure 2 but illustrates the terminal end portion of the solenoid with the insulating pants and disk and skirt member removed therefrom;

Figure 4 is a fragmental sectional view of the terminal end portion of the solenoid construction viewed as taken substantially along the line IVIV of Figure 2;

Figure 5 is an exploded view of the solenoid construction partly in section and with the solenoid coil removed therefrom; and

Figure 6 is a plan view of the split insulated disk used in the solenoid construction.

As shown on the drawings:

There is illustrated in Figure 1 a new and improved solenoid construction which, while being a solenoid of general utility, and of the plug-in type, is adapted to enjoy particular utility in such an installation as an integral solenoid valve.

The solenoid structure of the present invention includes a coil 10 which is wound on a spool 11 preferably so that the windings are placed thereon in coaxial cylindrical layers, and wound on the spool consecutively from the interior of the winding towards the exterior or maximum diameter thereof. This winding may be done by hand or on many well known types of solenoid winding machines and performed when the spool 11 is of multi-part construction, or it may be wound directly on the spool when it is of an integral construction.

In the particular embodiment thereof shown on the drawings, the spool 11 is preferably formed as a complete and integral one-piece structure having a hollow spindle 12 of cylindrical construction with a pair of integral end flanges 13 and 14 thereon and extending radially therefrom. Further, this spool 11 is preferably constructed from an insulating material such as nylon or the like.

A washer-like member 15, which is also formed of an insulating material such as nylon or the like, is carried on the spool barrel or spindle 12 which extends through an aperture 16 in the washer 15. This washer 15 serves to insulate the coil leads from the coil windings when the coil is wound on the spool.

In Figures 3 and 4 it may be seen that the lead wires 18 extend over the peripheral edge of the end radial flange 14 and thence along the inner face of the flange 14 between the flange 14 and the insulating washer 15. The inner winding lead 18 then passes through slot 17 in the washer 15 and the coil 10 is then wound on the spool body or spindle or barrel 12 in consecutive cylindrical layers until it builds up to desired radial dimension and has desired magnetic and electric properties. The outer winding lead then passes through the slot 17 in the washer 15 and thence between the washer and the inner face of the end flange 14.

These lead wires are then respectively aflixed to terminal lugs 19 and 2% which are secured in appropriate recesses 21 and 22 respectively in the outer face of the end flange 14, as by means of rivets 23 or the like. These terminal lugs 19 and are formed preferably to operate as electrical plug blades, and extend in a generally outward axially direction from the outer face of the end flange 14. The lead wires are fixed to the terminal lugs as by being wrapped thereon, as indicated generally at 24 for the lead 18, where the tenninal lugs are bent in an L shape. properly electrically conductively secured to the terminal lugs so that when the rivets 23 pass through the apertures 25 in the feet of the terminal lugs 19 and 20, then the entire assembly is positively secured in place. According to a preferred manner of construction of such solenoids, however, the terminal lugs are fixed to the flange before the coil is wound thereon or at least before the lead wires are connected to the terminal lugs.

To provide for the passage of the lead wires over the peripheral edge of the end flange 14, the end flange 14 has a pair of radial recesses 2626 in the edge thereof adjacent to the recesses 21 and 22 for the feet of the terminal lugs 19 and '29.

From a close examination of the solenoid as illustrated in Figures 3 and 4, it will be seen that the inner lead wire 18 is disposed in very close proximity to the outer face or outer windings 27 of the coil 10 and since these two portions of the coil are at a substantially maximum difference of potential, there is a tendency for arcing over the outer peripheral edge of the washer 15 and a breakdown of the installation on the inner lead wire 13 and the convolutions of the outer layer of winding 27 in the region of the washer 15.

To obviate this difliculty of possible arcing over the peripheral edge of the insulating washer 15' between the outer windings 27 of the coil 13 and the inner lead wire 18, there is provided, in accordance with the principles of the present invention, an insulator member 23 which is effective to insuiatingly cover the outer face of the radial end flange 14-, the peripheral edge of the washer 15, and the inner regions or portions of the terminal lugs 19 and 28 as illustrated in Figures 1, 2, 4 and 5. More particularly the insulator member 28 is provided with a base disk 29 which is axially centrally apertured as at 39 and provided with an inwardly extending axial flange 31 about the aperture 30, the outer radial face of which flange 31. engages the inner face of a flange 32 which limits the lug seating recesses 2i and 22. Extending substantially axially outwardly from the base disk 29 a pair of hollow pants members 33 and 34 cover the inner region of the terminal lugs 29 and 25 respectively. Further, at the outer peripheral edge of the base disk 29 there is integrally formed therewith a cylindrical skirt 3:3 which has an axial dimension sufflcient to extend over the radially outer peripheral edge of the washer 15. The inner radial dimension of the skirt 35' is such that it fits substantially snugly over the outer peripheral edge of the end flange 14 and over the outer peripheral edge of the washer 15.

The lead wires may be soldered or otherwise the radial edge of the flange 14-, I

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Any remaining gap is filled and the joints are covered by an insulating dip coating of varnish or potting compound which also fills the gap in the pants and about the terminals as by capillary action to further increase the moisture proof and are preventing qualities of the solenoid and arcing etween the inner lead Wire 18 and the outer turns 27 of the coil 19 is prevented or between the leads and a metal casing.

The pants members 33 and 34, which are substantially hollow, have inner enlarged hollow regions 36 and 37 respectively which are sufficiently enlarged to readily accept the securing and connecting turns 24 of the lead wires therewithin. At their outer ends, however, the pants members are shouldered, as at 38 and 39 so as to snugly fit the surfaces of the blade-like terminal lugs 19 and 20 respectively.

These pants members 33 and 34 are effective to insulate and protect the inner regions of the terminal lugs 19 and 20 and the lead wires which are connected thereto. In addition, the shoulder portions 38 and 39 aid in retaining the insulating member 28 in a properly operative position on the solenoid structure by the provision of swaged or the like ear-like members 40-40 on the thin edges of the terminal lugs 19 and 20 and so positioned thereon that they lie immediately outward of the shoulders 38 and 39 to bear resiliently thereagainst by the resilience of the insulating member 28.

The insulating member 28 may be assembled onto the structure merely by passing the terminal lugs 19 and 20 through the pants portions 33 and 39 until the retaining ears 4040 snap through and pass the shoulders 38 and 39. At that time the skirt 35 will overlie the outer peripheral edge of the end flange member 14 and the outer peripheral edge of the split washer 15 so as to completely insulate the terminal end of the solenoid structure yet leaving the outer ends of the knife bladelike plug-in terminal lugs 19 and 2t exposed for connection with an appropriate plug.

It will be observed from the foregoing that numerous variations and modifications may be effected in solenoid structures and the like without departing from the true spirit and scope of the novel concepts and principles of this invention. We, therefore, intend to cover all such modifications and variations as fall within the true spirit and scope of the novel concepts and principles of this invention.

We claim as our invention:

1. In a solenoid construction wherein a coil is wound on a spool formed from electrical insulating material and having a spindle with integral end flanges and ter minal lugs secured to the outer side of and extending generally axially outwardly from one of said end flanges, a split insulating washer on said spindle adjacent to the inner face of the flange carrying said terminal lugs, lead Wires extending from inner and outer windings of said coil to said terminal lugs respectively and through the split in said washer, and an integral insulator member carried by said terminal lugs and said one of said flanges, smd member covering the outer side of said one of said end flanges and having an annular skirt thereon extending over the periphery of said one of said end flanges and over the periphery of and ending at said washer thereby preventing arcing between the outer windings of said coil and the lead wire for the inner windings of said coil, and pants-like portions on said member extending axially outward along and covering the region of said terminal lugs close to one of said end flanges.

2. In a solenoid construction wherein a coil is wound on a spool formed from electrical insulating material and having a spindle with end flanges and terminal lugs secured to and extending generally axially outwardly from one of said end flanges, an insulating washer on said spindle adjacent to the flange carrying said terminal lugs, lead wires extending from inner and outer windings of said coil and through said insulating washer and secured to said terminal lugs respectively, and an insulating member covering the outer side of said one of said end flanges and carried by said terminal lugs and said one of said end flanges, said member having an annular skirt thereon extending over the outer periphery of said one of said end flanges and over the periphery of said washer thereby reducing tendencies for arcing between the outer windings of said coil and the lead wire for the inner windings of said coil, and pants-like portions on said member covering the region of said terminal lugs close to said one of said end flanges.

3. In a solenoid construction wherein a coil is wound on a spool formed from electrical insulating material and having a spindle with end flanges and terminal lugs secured to and extending generally axially outwardly from one of said end flanges, a split insulating washer on said spindle adjacent to the flange carrying said terminal lugs, lead wires extending from inner and outer windings of said coil to said terminal lugs respectively between said washer and said one of said end flanges, and an insulating member covering the outer side of said one of said end flanges and carried by said terminal lugs and said one of said end flanges, said member having an annular skirt thereon extending over the outer periphery of said one of said end flanges and over the periphery of said washer thereby reducing tendencies for arcing between the outer windings of said coil and the lead wire for the inner windings of said coil.

4. In a solenoid construction wherein a coil is wound on a spool formed from electrical insulating material and having a spindle with end flanges and terminal lugs secured to and extending generally axially outwardly from one of said end flanges, an insulating member covering the outer side of said one of said end flanges and carried by said terminal lugs and said one of said end flanges, and pants-like portions on said member covering the region of said terminal lugs close to said one of said end flanges, and an axial peripheral skirt on said member to insulate lead wires.

5. In a solenoid construction wherein a coil is wound on a spool formed from electrical insulating material and having a spindle with integral end flanges and terminal lugs secured to and extending generally axially outwardly from one of said end flanges, a split insulating washer on said spindle adjacent to the inner face of the flange carrying said terminal lugs, lead wires extending from said coil to said terminal lugs respectively and through said split in said washer and between said washer and said one of said end flanges, an insulating member covering the outer side of said one of said end flanges and carried by said terminal lugs and said one of said end flanges, said member having an annular skirt thereon extending over the periphery of said one of said end flanges and over the periphery of said washer thereby substantially preventing arcing between the outer windings of said coil, and pants-like portions on said member covering the region of said terminal lugs close to said one of said end flanges.

6. In a solenoid construction wherein a coil having inner and outer windings is wound on a spool formed from electrical insulating material and having terminal lugs thereon and lead wires connected to the terminal lugs from the inner and from the outer windings respectively, a washer on said spool separating said lead wires from the windings of the coil, and an insulating member covering the outer side of said one of said end flanges and carried on the spool and extending over a peripheral edge of the washer to substantially prevent arcing between the lead wire from the inner windings and the lead wire from the outer windings.

References Cited in the file of this patent UNITED STATES PATENTS 1,813,154 Franz July 7, 1931 2,214,151 Wagar Sept. 10, 1940 2,421,444 Tyne June 3, 1947 2,483,815 Easton Oct. 4, 1949 

